Although it is well known that the aged suffer a disproportionate share of the handicaps of impaired vision, relatively little is known about the real character of visual perceptual losses with age. This project is a developmental approach to visual perception, emphasizing spatial and temporal information processing in the last half of the life-span. Spatial vision will be analyzed via the spatial contrast sensitivity function and related measures. Procedures will be used which should distinguish between loses in vision which are attitudinal in origin (due to the cautiousness of the senescent observer) and those which are more likely to be sensory in origin. Differential loss in sustained and transient visual functions will also be investigated. Finally, some effects of stimulus uncertainty and distraction upon the visual performance of observers of various ages will also be studied.